class Solution {
public:
    int minimumTotal(vector<vector<int>>& f) {
        for (int i = f.size() - 2; i >= 0; --i)
        {
            for (int j = 0; j <= i; ++j)
            {
                f[i][j] += min(f[i + 1][j], f[i + 1][j + 1]);
            }
        }
        return f[0][0];
    }
};